Process of softening fibers and products thereof



Patented Oct. l9, 1937 rnoccss or SOFTENING rinses rnonnc'rs 'rnnmzor AND Howard Heckethorn, Oswego, N. Y., assignor of one-third to Warren K. Cooley, Silver Spring, Md., and one-third to Edward M. Schenke,

Chevy Chase, Md.

V No Drawing. Application October 20, 1930,

Serial No. 491,810

30 Claims. (01. 28-59) This invention relates to processes of softening fiber and products thereof; and it comprises a method of temporarily softening and lubricating rayon, acetate silk, natural silk and other fibers,

threads or filaments wherein fiber is treated with a substantially homogeneous mobile and thinly liquid composition containing an anhydrous solvent, usually a close boiling naphtha and a soap of an organic base, usually a soap of an ethanolamine; and the soap being one which will blend and go into homogeneous mixture with said solvent; all as more fully hereinafter set forth and as claimed.

In working fiber and thread, by spinning, throwing, twisting, winding, knitting, braiding, weaving and like operations, there is considerable expenditure of energy in and on the fiber and it is'customar-y to use a softening agent to reduce stiifness, aid fiexure and facilitate the relative 20 movement of the sub-fibers. For an ideal v softener the requirements are exacting and, to some extent, conflicting. Chief among these requirements is that the softening agent shall be easily and uniformly applied in the exactsmall quantities required prior to the working operation and that it shall be susceptible of quick and complete removal afterwards. None of the usual softening agents meets both these requirements to an extent desirable; and particularly with softening agents used for rayon and other forms of "synthetic fibers or filaments which have a quite different physical character from the older fibers. Hydrocarbon oils of the character of the wool oils are easily and" uniformly applied although not readily in exact small quantity but they ofier difiiculty in complete removal and their removal requires considerable care and precaution. So faras ease of removal is concerned the ordinary soda and potash soaps are good and they are desirable softening agents in the fiber. But to apply them in small quantity and secure even and uniform penetration of the fiber is not easy although it may be 'done as hereinafter pointed out. Emulsions of oil in various vehicles are often used but the emulsion must be very fine to prevent afiltering action by the fiber.

In the present invention these objections are overcome bythe use of a soap, or other softening agent. disolved in a suitable solvent to give a 50 mobilepenetratingsolntion. The quantityofsoftmingagmtisappliedtotheflberinthe solution and then the solvent evaporated on, leavingflieagentinphce. FormyI pooeslfremmesmps.

g5 mismalbnlhanorgnniebueleimhydrocarbons as this permits the use of a simple hydrocarbon solvent. Ordinary soda and potash soap may however be used with hydrocarbons if there be included a co-solvent enabling the production of a true solution; a solvent miscible with the hydrocarbon and capable of dissolving the soap.

Ordinary soda and potash soaps are not soluble in the usual hydrocarbons to form any true solution. The true solubility of a dry soap, soda or potash soap, as distinguished from a dispersion, in petroleum oils is probably less than 0.5 per cent by weight. On theother hand the substi tuted ammonias carrying hydrocarbon radicals are soluble in hydrocarbons to an extent dependcut upon the degree of substitution; and their soaps with fatty acids are also soluble. Various soaps of organic bases are useful and among them are the soaps formed by certain bases known as ethanolamines. The'ethanolamines are formed by the reacting ammonia with ethylene oxid. Similar bases are formed by propylene oxid and these are even more advantageous for the present purposes although commercially not so available. Monoethanolamine,- diethanolamine and triethanolamine are all applicable for the present purposes as is the commercial mixture of the three bases sold as "triethanolamine". As the fatty acid there may be used commercial oleic acid or any other convenient soap making acid. The free fatty acids from cocoanut oil are commerically available, are relatively cheap and are quite advantageous for the present purposes. These fatty acids, or any other fatty acid, may be directly saponifled by trlethanolamine. 7,

One advantage of the ethanolamine soaps in hydrocarbon solution for the present purposes is their relative tolerance for moisture. A solution of the soap in naphtha tolerates the presencev of a substantial amount of moisture without losing homogeneity.

In softening and lubricating rayon fiber as a rule the amount of soap requiredin the fiber is not more than about 4 to-6,parts by weight per 100 parts of fiber; and it is difficult, for reasons stated ante 'to get this small amount into and through the fiber uniformly. I therefore use a solution of the ethanolamine soap in a hydrocarbon solvent to produce impregnation with enough solvent to produce a mobile or thinly liquid composition. After the solvent is removed by evaporation, as by exposure to air. For this purpose any hydrocarbon solvent boiling with a fairly definite end point and not too volatile may be used. A solvent containing much heavy,ends" is objectionable since it leaves oil in the fiber which must be subsequently removed. The solvents should also be free, or reasonably free, of unsaturated bodies since these may lead to oxidation and tendering of the fiber. A good solvent for the present ,purposes is a material used by dry cleaners and known as Stoddard Solvent; a close boiling naphtha fraction having an over point of 300 F. and amend point of 410 F. This Stoddard solvent is sold under specifications requiring that the content of unsaturates shall be less than 5 per cent. However, any hydrocarbon oil, such as commercial benzol, toluene or naphtha fractions may be used; it being merely necessary thatv the flash point of the liquid used be high to preclude fire danger and tender or solvent.

that the end point be fairly definite to avoid contaminating the fiber with heavy oils.

For the present purposes a solution of ethanolamine soaps in Stoddard Solvent" carrying 2 to per cent of such soap may be used. Something depends on the permeability of the fiber and the amount of softener wanted in it. Solutions of these soaps, containing between 20 to 30 per cent of soap are efllcient. If the particular hydrocarbon used as a solvent or extending agent be too volatile it is often desirable to addsome carbon tetrachlorid to raise the fiash point. If there is much moisture to be dealt with, it is sometimes desirable to add some proportion of an ordinary solvent miscible with both water and hydrocarbons, such as butyl alcohol, cyclohexanol, etc. The amount of such an addition, however, is usually small; it being regarded as desirable that the softening and lubricating agent for the present purposes consist mainly of the organic base soap and a dry hydrocarbon ex- In the performance of the present process, the starting materials in any suitable form, such as threads, yarns, filaments or the like, are impregnated with a mobile solution of the softening and lubricating agent in a volatile hydrocarbon solvent of the character stated. The volatile solvent is then evaporated off and, if desired, recovered. The impregnated materials thus obtained are subjected to any of the usual operations, such as spinning, weaving, twisting or the like, to form the desired textile articles. such operations are completed, the textile products are worked in water or dilute soap solutions, to wash out and remove the softening and lubricating agent, and the washed products rinsed in clear water and then dried.

While I have disclosed my invention more particularly in its use with a hydrocarbon solution of a soap having an organic base and while I regard this as the most advantageous embodiment of my invention, the principles of my invention can be used with other compositions. I can for instance dissolve 20 or 30 per cent of potash soap in a compound solvent consisting of "Stoddard Solvent admixed with butanol or cyclohexanol or any other moderately high boiling .organic solvent which will act as a co-solvent for soap and'for. hydrocarbon. This solution of soap is applied to the fiber orxthread as before to secure impregnation with the necessary exact 70 'small quantity of soap, the solvent is removed by evaporation, the fiber worked in such was as a may be necessary and the impregnating soap removed by washing as before.

The butanol or cyclohexanol has another function in addition to acting'as aco-solventi since After" it takes care of the water of condition taken up from the fiber by the mixed solvent.

My dry solvent-soap solution may be used to impregnate all types of textile materials with a softening and lubricating agent. Animal, vegetable or synthetic fibers, filaments, or threads may be treated. Typical examples of animal fibers are natural or boiled-off silk, tussah silks, wool, hairs, etc. Of vegetable fibers there may be mentioned cotton: mercerized cotton, linen, ramie, hemp, jute, manila, kapok and the like. All synthetic fibers, such as viscose, cuprammonium, nitrocellulose and cellulose acetate silks, may be advantageously treated with my compositions.

The impregnated textile materials can then be worked in any desired manner to fabricate the material into various products. They may be subjected to any of the usual manipulations such as spinning, throwing, twisting, winding, knitting, braiding or weaving. The desired manipulations may be performed with great facility and speed without any of the danger of damaging the material usually attending such manipulations of these materials.

After performing the desired working the softening. and lubricating agent, may be, as stated, easily and quickly removed by simple washing;

complete removal is readily efiected. This may as trisodium phosphate or soda ash, may be added to the dilute soap solution. 0r these dilute alkali solutions may be used alone for the washing. However, the use of dilute alkaline solutions or their addition to dilute soap solutions is only recommended, when it is desired there be simultaneous cleansing to remove foreign bodies originally present in the textile material or which may have been picked up during the working or manipulation. When, however, it is necessary to remove only the softening and lubricating agent from the impregnated material, alkalies etc., are not needed.

Frequently, after working, it is desired to dye the textile material. With softening and lubricating agents of the ethanolamine-fatty acid soap Ynolamine soap, most dye baths are unaffected. This type of soap has no salting out effect, like that of ordinarysoaps. In fact, it aids in the penetration of the dye into the material. After dyeing the material is rinsed in the. customary manner.

The following examples serve to illustrate certain embodiments of my invention; but they in.

no way limit the broad scope of my invention as set forth ante. The aregiven as parts by weight.

Examples i to a set forth typical compositions which contain an organic base-soap dissolved an organic hydrocarbon solvent.

Example 1 235 parts of cocoanut oil acids are saponifled with 120 parts commercial triethanolamine to obtain a softening and lubricating agent. The soap thus obtained is mixed with and dissolved in a hydrocarbon solvent; which may be a mixture of 1345 parts of Stoddard Solvent and 36 parts of butyl cellosolve or hexalin. The composition thus formed may be used to impregnate all types of textile materials. Various other fatty acids may be used in lieu of the fatty acids of cocoanut oil. Also the type and proportion of the hydrocarbon solvent may bevaried within wide limits.

Example 2 220 parts of commercial oleic acid are saponifled with 100 parts of commercial triethanolamine. The soap thus obtained is then dissolved in an oily solvent comprising 1,000 parts of Stoddard Solvent, 400 parts of carbon tetrachlorid and 100 parts of colorless high boiling mineral oil. The mineral oil in the small amount stated is easily removed in washing out the soap. This oil is itself a softening and lubricating agent.

This composition not only contains an organic base-soap as a softening and lubricating agent but also an added softening agent, namely, colorless mineral oil. The carbon tetrachlorid also adds certain desired properties to the composition. The stated composition may also be varied within-wide limits and in place of the mineral oil, as an added softening and lubricating agent, other softening and lubricating agents may be substituted in lieu thereof to produce an impregnating composition containing two or more softening and lubricating agents.

In the above examples the hydrocarbon solvent has Stoddard Solvent as a basis, but various other organic solvents commonly known as dry solvents in dry cleaning; may be' used in lieu thereof either alone or in various mixtures. (The followingexample is typical of such modifications.

- Example 3 220 parts of commercial oleic acid are saponified with 100 parts of triethanolamine. The resulting soap is dissolved in a dry solvent comprising 100 parts of carbon tetrachlorid and 40 parts of hexalin. The hexalin imparts certain advantageous properties and functions also as a co-solvent, that is a blending or carrying agent, assisting in blending the softening agent withtetrachlorid. The homogeneous impregnating compositions obtained are, or behave, as true solutions. In place of the hexalin various other 00- solvents, for instance, butanol, amyl' alcohol, dellosolve or butyl cellosolve" may be used. Chemically cell'osolve is mono-ethyl ether of ethylene glycol.- Alsocertain amounts of free fatty acids exercise like action. Free fatty acids may be added to the impregnating compositions .or the fatty acids used maybe only partially saponifled, leaving an excess. of free fatty acids.

The above examples illustrate the use of an organic base-soap type of softening and lubricating agent. However as stated by a variation in solvents, there may be used as a softening and lubricating agent soaps obtained by combining fatty acids with alkalies, namely, caustic soda or potash. The following example illustrates this modification.

Example 4 100 parts of commercial-oleic acid are saponifled withalcoholic caustic potash; using a mix ture of 19 parts of caustic potash with 30 parts of methyl alcohol. The reaction mixture thus obtained is mixed with'a hydrocarbon solvent comprising 450 parts of Stoddard Solvent and 35 parts of hexalin. A homogeneous impregnating composition is obtained, which may be eflfective- 1y used in our process. In making impregnating compositions of this type it is advisable to have a substantial amount of a co-solvent, that is, blending or carrying agent, such as the hexalin and alcohol in the above composition.

The above examples are merely typical embodiments and compositions under the present invention may be varied over a wide range to suit them for a. particuiar'application or use. All these compositions comprise essentially an organic or hydrocarbon solvent of the type known as dry solvents with a softening and lubricating. agent dissolved therein.

Various hydrocarbon and-other organic solvents may be used in mak- 7 ing these compositions; Stoddard Solvent is advantageous but other organic solvents such as- .carbon tetrachlorid, ethylene dichlorid, chloroform, trichlorethylene, tetrachlorethane, isopropanol or.other alcohols, or-any desired mixture or mixtures of these solvents may be used. The softening and lubricating agent may be advantageously, organic base-fatty acid soap-like products for the stated reasons.

Where additional softening agents are used they may be added, the. solvent employed being one which will dissolve. mineral oil, vegetable oil,

animal oil, sulfonated oils, etc. At times it is desirable to use a modicum of such an oil as olive oil, castoroil, rape seed oil, soy bean, cottonseed oil etc. neatfoot oil, olein. Turkey red oil may be incorporated.

Sometimes it is desired to dye textile materials prior to fabricating them into textile products. with my compositions it is possible to simultaneously impregnate and dye the textile material.

For this purpose suitable dyes may be incorpo-- rated'with my impregnating compositions. In

certain textile operations it is desired to easily identify certain materials during the processing; to this end they are dyed. In such instances, the dyes may be such that they may be stripped from the fiber when it is washed to remove the softening and lubricating agent; the dyeing being merely for identification during the process.

Liquid compositions under the present invention may be applied to thread or fabric tosecure A impregnation in any of the usual ways; as by dipping or immersing, spraying, transferring by rolls,

etc. Capillary action may be relied upon; a wick action so to speak. In impregnation the material to be treated may be handled in any of the usual ways, as on bobbins, skeins, cones, etc.

In removing the solvent this may be done by simple exposure to air which may be at atmostions are moredesirabie than those hereinbefore recited.

Where the word silk is used in the appended claims as specifying the particular type of fiber, it is used in its broad sense and includes, in addition to natural silk, the various types of artificial fibers which are generally considered as artificial silk.

What I claim is: 1. In a process for temporarily softening and lubricating textile fibers which are to be used in textile operations, the step which comprises impregnating such fibers with a liquid solution 7 capable of rendering said fibers soft and pliable and readily workable on textile machines, said solution comprising a water-soluble soap capable of acting as a softening and lubricating agent and an organic solvent therefor in which the textile fibers are insoluble.

2. In a process for temporarily softening and lubricating textile fibers which are to be used in textile operations, the step which comprises impregnating such fibers with a liquid soluticn'capable of rendering said fibers soft and pliable and readily workable on textile machines, said solution comprising a water-soluble soap capable of acting as a softening and lubricating agent and a volatile hydrocarbon solvent therefor.

3. In a process fortemporarily softening and lubricating textile fibers which are to be used in textile operations, the step which comprises impregnating such fibers with a liquid solution capable of rendering said fibers soft and pliable and readily workable on textile machines, said .solution comprising naphtha and a water-soluble soap capable of acting as a softening and lubricating agent dissolved therein.

4. In a process for temporarily softening and lubricating textile fibers which are to be used in textile operations, thestep which comprises impregnating such fibers with a liquid solution capable of rendering said fibers soft and pliable and readily workable on textile machines, said solution comprising an organic solvent in which the textile fibers are insoluble, a softening and lubricating agent normally insoluble therein. and a co-solvent for the organic solvent and the softening and lubricating agent.

5. In a process for temporarily softening and lubricating textile fibers which are to be used in textile operations, the step which comprises impregnating such fibers with a liquid solution capable of rendering said fibers soft and pliable and readily workable on textile machines, said solution comprising an organic solvent in which the fibers are insoluble, a water-soluble soap capable of acting as a softening and lubricating agent which is. normally insoluble in said organic solvent, and a co-solvent for the organic solvent and soap.

6. .In a process for temporarily softening and lubricating textile fibers which are to be used in textile operations, the step which-comprises impregnating such fibers with a liquid solution capable of rendering said fibers soft and pliable and readily workable on textile machines, said solution comprising a volatile hydrocarbon solvent, a water-soluble soap capable of acting as a. softening and lubricating agent which is normally insoluble I therein and a co-solvent for the volatile hydrocarbon solvent and the soap.

7. In a process for temporarily softening and lubricating textile fibers which are to be used in textile operations, the step which comprises impregnating such fibers with a liquid solution capable of rendering. said fibers soft and pliable and readily workable on textile machines, said solution comprising naphtha, a water-soluble soap normally insoluble therein and a co-solvent for the naphtha and soap.

8. 'In a process for temporarily softening and lubricating textile fibers which are to be used in textile operations, the step which comprises impregnating such fibers with a liquid solution capable of rendering said fibers soft and pliable and readily workable on textile machines, said solution comprising an organic solvent in which the textile fibers are insoluble, a softening and lubricating agent normally insoluble in said organic solvent and a co-solvent for the organic solvent and the softening and .lubricating agent from the class consisting of alcohol, amyl alcohol, cyclo-hexanol,

butanol and monoethylether of ethylene glycol.

9. In a process for temporarily softening and lubricating textile fibers which are to be used in textile operations, the step which comprises impregnating such fibers with a liquid solution capable of rendering said fibers soft and pliable and readily workable on textile machines, said solution comprising an oil, a soap capableof acting as a softening and lubricating agent and an organic solvent for the oil and soap in which the fibers are insoluble.

10. In a process for temporarily softening and textile operations, the step which comprises impregnating such fibers with a liquid solution capable of rendering said fibers soft and pliable and readily workable on textile machines, said solution comprising a water-soluble soap capable of acting as a softening and lubricating agent and an organic solvent therefor in which the textile fibers are insoluble, subsequently working the fiber, and thereafter washing said impregnated I fiber to remove the soap.

solution comprising an organic solvent in which the textile fibers are insoluble, a water-soluble soap capable of acting as a softening agent which is normallyinsoluble in said organic solvent and a cc-solvent for the organic solvent and soap, re-

moving the solvent and the co-solvent, subselubricating textile fibers which are to be used in 1 quently working the fiber, and thereafter washing said impregnated fiber to remove the soap.

12. In a process for temporarily softening and lubricating silk which is to be used in a textile operation, the step which comprises impregnating the silk with a liquid solution capable of rendering thesilk soft and pliable and readily workable on textile machines, said solution comprising a water-soluble soap capable of acting as a softening and lubricating agent and an organic solvent for the soap in which the silk is insoluble. '13. As anew composition for softening and iiibricating textile fibers which are to be used in textile operations, a liquid solution comprising an organic solvent in which the textile fibers are insoluble and a water-soluble soap capable of acting as a softening and lubricating agent dis solved in the solvent, said solution being capable of readily penetrating a textile fiber by gravity and rendering the same soft and pliable and readily workable on textile machines.

14.-As a new compositionforsoftening and lubricating textile fibers which are to be used in textile operations, a liquid solution comprising a volatile hydrocarbon solvent and a water-soluble soap capable of acting as a softening and lubrieating agent dissolved therein, said solution'being capable of readilypenetrating a textile fiber by gravity and rendering the same soft and pliable and readily workable on textile machines.

15. As a new composition for softening and lubricating textile fibers which are to be used in textile operations, a liquid solution comprising naphtha and a water-soluble soap capable of acting as a softening and lubricating agent dissolved in the naptha, said solution being capable of readily penetrating a textile fiber by gravity and rendering the same soft and pliable and readily workable on textile machines. I

16. As a new composition for softening and lubricating textile fibers which are to be used in textile operations, a liquid solution comprising an organic solvent in which the textile fibers are insoluble, at least one softening and lubricating agent normally insoluble in said organic solvent and a co-soivent for the organic solvent and the softening and lubricating agent, said solution being capable of readily penetrating a textile fiber by gravity and rendering the same soft and pliable and readily workable on textile machines.

17. As a new composition for softening and lubricating textile fibers which are to be used in textile operations, a liquid solution comprising an organic solvent in which textile fibers are insoluble, a water-soluble soap capable of acting as a softening and lubricating agent which is normally insoluble in said organic solvent, and a co-solvent for the organic solvent and the soap, said solution being capable of readily penetrating a textile fiber by gravity and rendering the same soft and pliable and readily workable on textile machines. 18. As a new composition for softening and lubricating textile fibers which are to be used in textile operations, a liquid solution comprising a volatile hydrocarbon solvent, a water-soluble soap capable of acting as a softening and lubricating.

agent which is normally insoluble in said volatile hydrocarbon, and a co-solvent for the volatile hydrocarbon and the soap, said solution being capable of readily penetrating a textile fiber by gravity and, rendering the same soft and pliable and readily workable on textile machines.

19. As a new composition for softening and lubricating textile fibers which are to be used in textile operations, a liquid solution comprising naphtha, a water-soluble soap capable of acting as a softening and lubricating agent which is normally insoluble in said naphtha, and a co-solvent for the naphtha and soap, said solution being capable of readily penetrating a textile fiber by gravity and rendering the same soft and pliable and readily workable on textile machines.

20. As a new composition for softening and lubricating textile fibers which are to be used in textile operations, a liquid solution comprising an organic solvent in which textile fibers are insoluble and a water-soluble soap capable of acting as a softening and lubricating agent dissolved in the solvent, the softener and lubricant compris.

soap capable of acting as a softening and lubri eating agent dissolved therein, the softener and lubricant comprising at least of the solution, said solution being capable of readily penetrating a textile fiber by gravity and rendering the same soft and pliable and readily workable on textile machines.

22. As a new composition for softening and lubricating textile fibers which are to be used in textile operations, a liquid solution comprising acting as a softening and lubricating agent dis solved in the naphtha, the softener and lubr'i cant comprising at least 10% of the solution, said solution being capable of readily penetrating a textile fiberby gravity and rendering the same soft and pliable and readily workable on textile machines.

' 23. As a new composition for softening and lubricating textile fibers which are to be used in textile operations, a liquid solution comprising an oil, a water-soluble soap capable of acting as a softening and lubricating agent and an organic solvent for the oil and soap in which the fibers are insoluble, said solution being capable of readily penetrating a textile fiber by gravity and rendering the same soft and pliable and readily workable on textile machines.

24. As a new composition for softenlngand lubricating textile fibers which are to be used in textile operations, a liquid;solutlon comprising an organic solvent in which textile fibers are .insoluble, and an ethanol amine soap dissolved in the solvent, said solution being capable of readily penetrating a textile fiber by gravity and rendering the same soft and pliable and readily workable on textile machines.

25. As a new composition for softening and lubricating textile fibers which are to be used in textile operations, a liquid solution comprising an organic solvent in which the textile fibers are insoluble, a softening and lubricating agent other than a soap, and an ethanol amine soap, the softening and lubricating agent and the soap being dissolved in the solvent and the solution being capable of readily penetrating a textile fiber by gravity and rendering the same soft and pliable and readily workable on textile machines.

26. As a new composition for softening and lubricating textile fibers which are to be used in textile operations, a liquid solution comprising an organic solvent in which the textile fibers are insoluble, a softening and lubricating agent normally insoluble in said organic solvent, and

a co-solvent for the organic solvent and the softening and lubricating agent from the class consisting of alcohol, amyl alcohol, cyclo-hexa'nol, butanol and monoethylether of ethylene glycol, said solution being capable of readily penetrating the textile fibers by gravity and rendering the same soft and pliable and readily workable on textile machines. i

27. In a process for temporarily softening and lubricating synthetic textile fibers which are to be used intextile operations, the step which comprises impregnating the fibers with a liquid solution capable of rendering said fibers soft and pliable and readily workable on textile machines, said solution comprising a water-soluble soap capable of acting as a softening and lubricating agent and an organic solvent for the soap in which the fibers are insoluble.

28. In a process-for temporarily softening and lubricating textile fibers composed of cellulose acetate which are to be used in textile opera- 10 naphtha and a water-soluble soap capable of fibers with a liquid solution capableoi. rendering said fibers soft and pliable and readilyworkable on textile machines, said solution comprising a water-soluble soap capable of acting as a soitening and lubricating agent and an organic solvent for the soapdn which the fibers are insoluble.

29. In a. process for temporarily softening and lubricating synthetic textile fibers which are to be used in textile operations; the step which comprises impregnating the fibers with a liquid solution capable of rendering said fibers soft and pliable and readily workable on textile machines, said solution comprising an organic solvent in which the synthetic fibers are insoluble, a watersoluble soap capable of acting as a softening 9,096,705 tions, the step which comprises impregnating the agent which is normally insoluble in said organic solvent and a co-solvent for the organic solvent and the soap.

30. In a process for temporarily softening and lubricating textile fibers composed oi. cellulose acetate which are to be used in textile operations,

' the step which comprises impregnating the fibers with a liquid-solution capable oi'rendering said fibers soft and pliable and readily workable on textile machines, said solution comprising an organic solvent in which the fibers are insoluble,

a water-soluble soap capable oi acting as a sott- 

